The present invention relates to a dispenser for a roll of web material, and particularly to a sanitary dispenser that automatically dispenses a measured amount of material upon a user grasping and pulling the xe2x80x9ctailxe2x80x9d end of the roll material.
A number of dispensing devices are well known in the art for dispensing and cutting rolls of web material such as paper toweling. With such dispensers, the process of dispensing and cutting the web material is carried out automatically by a user pulling on the free xe2x80x9ctailxe2x80x9d end of the web material that extends from a dispensing slot in the apparatus. In a typical configuration, the web material is engaged against a rough friction enhancing surface of a feed drum and the action of pulling the web tail causes the drum to rotate. The drum includes a drive mechanism and, after the initial pull on the web tail by a user, the drum is driven a predetermined rotational degree to dispense a metered amount of the material. A cam driven cutting mechanism may be provided in the rotating drum that pivots out of a slot in the drum to automatically cut the web at the proper length. The dispensers typically include a stored energy mechanism, such as an eccentric cam, that is spring loaded during the initial rotation of the feed drum. This device causes the drum to continue to rotate after the web has been cut. This action causes an additional length of the web material to be feed out of the dispensing slot as the tail for the next dispensing sequence. These types of dispensers are commonly referred to as xe2x80x9cno-touchxe2x80x9d or xe2x80x9csanitaryxe2x80x9d dispensers because the user does not manually operate any portion of the drive or cutting mechanism and does not actually have to touch the dispenser. The user only touches the tail end of the web material.
Although effective, the conventional mechanical sanitary dispensers utilizing automatic mechanical cutting and feeding mechanisms can be relatively complicated from a mechanical component standpoint and expensive to manufacture and maintain. Also, some users have noted that such dispensers present an inordinate amount of resistance to pulling a towel from the dispenser. This may be particularly true when the initial pulling action by the user also provides the force needed to load a spring of the automatic tail feeding mechanism. Thus, web materials with relatively high tensile strength must be used with such dispensers.
Advances have been made in the art relating to electronic sanitary towel dispensers. With such dispensers, the unit is typically activated upon detection of motion of a user""s arm or hand. A motor is subsequently energized through a control circuit and power source to drive a feed roll and thus dispense a measured length of material. The user then grabs the exposed material and pulls it at some angle to the dispenser cover causing the sheet of material to separate on a cutting edge or serrated tear bar. The cycle is repeated for the next user.
U.S. Pat. No. 3,730,409 discloses an electronic dispenser wherein initially a full measured length of towel hangs out of the dispenser. A user grabs and separates the towel by pulling it against a tear bar. A force activated switch is configured with the tear bar that activates a dispenser motor through a power source and electronic circuit upon the user tearing the towel. The motor then drives a feed roll to deliver a full measured length of towel material outside of the dispenser cabinet where it hangs for the next user to grab and tear. WO 00/63100 describes an electronic dispenser with a similar operating principle. These dispensers have the disadvantage that the entire towel sheet hangs out of the dispenser prior to use. This is obviously not a sanitary or desirable condition.
A drawback with conventional electronic dispensers is that they operate using an active sensor to trigger the dispensing sequence. The different types of sensors vary in their method of operation, but all generally operate on the principle that the presence of the user triggers the dispenser without the user touching the dispenser. The sensor may detect body motion, infrared heat, or some other physical attribute of the user. Regardless of how they operate, such sensors are always xe2x80x9conxe2x80x9d and thus continuously draw current from the power source. This greatly reduces the battery life of such systems resulting in frequent battery replacement and maintenance.
Another drawback to conventional electronic dispensers is performance reliability. The systems are prone to false xe2x80x9ctripsxe2x80x9d due to temperature variations, consumer traffic and movement, stray RF signals, etc., resulting in the dispensing of sheets when no bona fide user has actually attempted to activate the dispenser. These false trips waste paper, drain the system batteries, and frustrate patrons.
The present invention relates to an electrical sanitary dispenser that addresses at least some of the drawbacks of conventional mechanical and electrical dispensers.
Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The present invention provides an electronic dispenser for dispensing measured sheets from a roll of web material. The dispenser is not limited to dispensing any particular type of rolled web material, but is particularly useful for dispensing measured sheets of towel material and will be referred to and illustrated herein as a towel dispenser for ease of explanation. The dispenser is a xe2x80x9csanitaryxe2x80x9d or xe2x80x9cno-touchxe2x80x9d dispenser in that the user only touches the tail of the material extending out of the dispenser to dispense a measured sheet and need not activate or manually manipulate a dispensing mechanism or any portion of the dispenser during normal use.
The dispenser includes a housing of any shape, configuration, or aesthetic appearance. A roll carrier is disposed in the housing for rotationally carrying a roll of the web material. A dispensing slot is defined in the housing through which measured lengths of the web material are dispensed. A length of the web material extends out of the dispensing slot and defines a xe2x80x9ctailxe2x80x9d that a user grasps and pulls in order to start the automatic dispensing sequence.
An electrically driven feed mechanism is disposed in the housing to dispense the sheets of web material therefrom. An electric motor is configured for driving the feed mechanism. A power source, such as a battery or external power circuit, is provided to power the motor and associated circuitry.
In one particular embodiment, the feed mechanism includes a driven feed roller mechanically engaged by the motor. A pressure roller may be disposed against the driven feed roller so as to define a nip through which the web material passes in its running path through the dispenser.
A sensor is disposed within the housing at a location along the running path of the web material. This sensor is positioned and configured to detect a parameter within the housing that changes or varies as a result of a user grasping and exerting an initial pulling force on the web tail extending out of the dispensing slot. The xe2x80x9cparameterxe2x80x9d sensed may be any number of features or variables. For example, in one embodiment, the sensor is a contact type sensor against which the web material presses in its running path. In a static or dormant mode, such as when the tail is simply hanging from the dispenser, the web material does not move and very little force is exerted by the material against the sensor. However, upon a user grasping and pulling on the web tail, the material within the dispenser is drawn taunt and/or its path is changed or otherwise deviated. The sensor may be deflected by the change in the web material or simply detect the change in the web path resulting in activation of the automatic dispense sequence.
In an alternate embodiment, the sensor need not be in contact with the web material. For example, the sensor may be a motion type of sensor that directly or indirectly detects movement of the web material upon a user initially pulling on the web tail. In one particular embodiment, the sensor may detect rotational movement of a roll or like member that is caused to rotate by the user pulling on the tail.
Regardless of the type of sensor or sensed parameter, the sensor has a dormant mode in which it is not supplied with power from the power source. In other words, the sensor is not always xe2x80x9con,xe2x80x9d but is only activated upon an initial pull on the tail material. Thus, the sensor is not a drain on the power supply.
A control circuit may be provided to coordinate operation of the various components. For example, a circuit may be in communication with the power supply, motor, and sensor. Activation of the sensor may cause a contact in the control circuitry to close wherein power is then supplied to the motor to dispense a length of the web material. A relatively simple timing circuit may be provided that controls the operating time of the motor. Thus, the length of web material dispensed is controlled by the run time of the motor. There are numerous other methods available to those skilled in the art to control the length of web material dispensed by the feed mechanism.
The dispenser is further provided with a web cutting or severing device to enable the user to cut the dispensed length of web material into an individual sheet. Various suitable automatic and manual cutting devices are known in the art and may be used with the present dispenser for this purpose. For example, the automatic dispensing sequence may include an automatic cutting sequence as well. However, in order to conserve battery power and minimize complexity and manufacturing costs, it may be desired to utilize a relatively simple manual cutting device, such as a tear bar (blade) disposed proximate to the dispensing slot. To sever the web material, the user simply pulls the material at an angle against the tear bar.
After the web has been severed, provision should be made that a tail is presented for the next user. In this regard, the dispenser may include a cutting sensor disposed to detect the manual web cutting sequence and to generate a corresponding signal causing the feed mechanism to subsequently dispense a second measured length of the web material from the dispensing slot to define the tail for the next user. In one particular embodiment, the web cutting sensor may be a tear bar sensor disposed to detect movement or deflection of the tear bar upon the user pulling the web material against the bar. In another embodiment, a sensor may be deployed to detect deflection or movement of the web material as it is pulled against the tear bar by the user. This sensor may be the same sensor used to detect the initial pull on the tail by user, or a different sensor.
The invention will be described in greater detail below by reference to embodiments thereof illustrated in the figures.